A liquid ejection apparatus used in an inkjet printer or, namely, an inkjet head includes: a plurality of pressure chambers to which ink as a liquid is introduced; a plurality of electrostatic capacitive loads such as piezoelectric elements which apply pressures for introducing and ejecting the ink; a plurality of electrodes for applying a drive voltage to the piezoelectric elements; a nozzle plate (also referred to as an orifice plate) comprising nozzles for ejecting the ink, at positions respectively corresponding to the pressure chambers; and a mask plate which protects the nozzle plate. Electrostatic capacitive actuators are respectively constructed by the piezoelectric elements and the electrodes. The mask plate is grounded in order to release static electricity generated by contact with recording media.
Since the mask plate is connected to the ground, a great potential difference appears between the electrodes in the pressure chambers and the mask plate. When aqueous ink is used, the potential difference causes electrolysis of moisture in the ink in the pressure chambers, and produces foreign substances such as air bubbles and condensate in the ink or dissolves or corrodes the electrodes. When foreign substances are produced, flow of ink from the pressure chambers to the nozzles is hindered, and at worst, the nozzles clog due to the foreign substances and disable ejection of ink. Further, the potential difference may change the quality of the ink.